Not applicable.
Not applicable.
The present invention relates generally to a multi-position ratchet mechanism for holding a surgical retractor blade and, more particularly, a three-dimensional ratchet mechanism which permits the retractor blade to be tilted into the wound and retracted at the same time while also enabling angular adjustment of the retractor blade to facilitate deployment in deep wounds.
In surgical operations of the chest or abdomen, it is often necessary to use a retraction apparatus to retain tissue away from the operative site. Typically, the retraction apparatus includes a housing member configured to lock onto a circumferential ring located above the operative site. To maintain the ring in a fixed position, the ring can be connected to a support post adjacent to the site. An extension arm may be attached to the support post for supporting the circumferential ring. Within the housing member a retraction blade can usually be found for grabbing the tissue around the surgical incision. The housing member can also include a ratcheting mechanism and/or a tilting mechanism to draw the retraction blade away from the incision, thereby effecting the pulling away and/or lifting of the tissue around the incision to expose the desired surgical area. Examples of such retractor systems are disclosed in U.S. Pat. Nos. 4,254,763, 4,424,724 and 5,375,481.
Yet despite these retraction systems, there continues to be a need for a retraction system which can provide the retractor blade with even more flexibility of movement for use in deep wounds. It would therefore be advantageous to have a ratchet mechanism which can not only enable the tilt and the movement of the retractor blade in and out of the wound site, but also the angular adjustment, or rotation, of the retractor blade without having to remove the ratchet from the ring. The ability to rotate or tilt the retractor blade as well provides the surgeon with even greater control over the exposure of the surgical area.
The present invention achieves the aforementioned goals by providing a three-dimensional tilt ratchet mechanism that is able to rotate, pivot, and bend forwards or backwards with ease. The present invention provides a device for multi-dimensional movement and placement of a retractor blade which comprises a first member adapted to receive a stem of a retractor blade. The first member has a locking mechanism effective to enable selective lateral adjustment of the retractor blade relative to the first member. Also provided is a second member to which the first member is mated. The first member is vertically pivotable with respect to the second member to enable selective vertical pivoting adjustment of the retractor blade relative to the second member. A rotator indexing body is mated to the second member and is adapted to mount onto a rim of a surgical support. The second member is rotatable with respect to the rotator indexing body such that the first member, the second member and the retractor blade are able to selectively rotate about the longitudinal axis of the rotator indexing body.
In one aspect of the present invention, the second member is rotatable up to approximately 30 degrees about the longitudinal axis of the rotator indexing body. The device further includes a ratchet release bar pivotally connected to the second member for adjustably maintaining the retractor blade a fixed vertical distance from the second member. The locking mechanism can comprise a spring biased pawl, and a ball plunger assembly is included on the rotator indexing body for achieving an interference fit between the rotator indexing body and the rim of the surgical support. To fix the rotator indexing body in a fixed position with respect to the second member, the rotator indexing body includes a plurality of indents extending circumferentially about the rotator indexing body that are engaged by a locking pin extending from the second member.
In one exemplary embodiment of the present invention, the device comprises a retractor blade holder having an opening therein for receiving a retractor blade and a curved ratchet extending therefrom. A pawl is pivotally connected to the retractor blade holder and adjustably maintains the retractor blade a fixed distance from the retractor blade holder. The retractor blade holder is pivotally connected to a housing member that includes a channel for insertion of the curved ratchet therethrough. A ratchet release bar pivotally connected to the housing member enables the retractor blade holder to be adjustably maintained a fixed distance from the housing member. The housing member includes an opening configured to receive and rotatably hold a rotating indexer. The rotating indexer has a slot therein for attaching to a ring secured to a stationary post, and further includes a plurality of indents extending circumferentially about the rotating indexer. A locking pin is provided which extends from the housing member to engage the plurality of indents to maintain the rotating indexer in a fixed angle with respect to the housing member.
In one aspect of the exemplary embodiment, the curved ratchet includes a plurality of teeth and the ratchet release bar includes an undercut engageable with the plurality of teeth on the curved ratchet. The ratchet release bar can include a thumb release tab for ease of manipulation. A spring coil is provided for biasing the pawl to a desired position, and for applying a spring force against the ratchet release bar. Further, an indexer coil is provided with the rotating indexer to maintain a spring bias force on the rotating indexer while held inside the housing member. The ratchet device of the present invention also includes a ball plunger assembly on the rotating indexer for achieving an interference fit between the rotating indexer and an attached ring. The ball plunger assembly can comprise a spring coil having a threaded end and a ball at an opposite end.
Further features of the invention, its nature and various advantages, will be more apparent from the accompanying drawings and the following detailed description of the drawings and the preferred embodiments.